Retinal degeneration, resulting, for example, from choroidal neovascularization (“wet AMD”) or from buildup of cellular debris between the retina and the choroid (“dry AMD”), is one of the major causes of blindness in the world today. Cai et al. (2012) Front Biosci. 17:1976-95. Similarly, degeneration and death of photoreceptor cells (rods and cones), as occurs in Retinitis pigmentosa, can also lead to deterioration and/or loss of vision. Accordingly, treatments that block and/or reverse retinal, degeneration, in particular treatments that restore photoreceptor function, are needed.